3D printing formwork for casting artificial habitats for Northern House Wren (Troglodytes aedon)

Abstract Rapid urbanization and construction drive land-cover change, environmental degradation, and novel ecosystems, with major implications for biodiversity. Cavity-nesting birds are among the taxa facing reduced availability of suitable nesting sites, which can negatively affect local populations. Grounded in more-than-human design, this study extends the use of computational design and digital fabrication in architecture beyond predominantly human-centered applications by developing and testing artificial nesting habitats for the Northern House Wren ( Troglodytes aedon ). We examined whether alternative habitat material, cast concrete, compared with traditional wooden nest boxes, was associated with differences in nest use and reproductive success. We designed a habitat prototype —Nook— informed by (1) preserved nests built inside conventional wooden nest boxes and (2) established guidelines for standard nest-box design. To enable repeatable production, we additively manufactured plastic formwork for casting ten concrete habitats, which were installed in the field alongside ten traditional wooden nest boxes. During the 2025 breeding season (25 June–2 August), birds used 9 of 10 concrete habitats compared with 3 of 10 wooden boxes. Among used units, the success rate (boxes producing young/boxes used) was 88.9% for concrete habitats and 33.3% for wooden boxes. These field observations provide preliminary evidence that cast-concrete habitats can support successful breeding and, under the conditions tested, perform comparably to or better than conventional wooden nest boxes. More broadly, the study contributes a reproducible workflow for translating ecological requirements into fabricated habitat prototypes and evaluating them with ecological performance criteria.